This invention relates to a plough for winning material in a longwall working, and to a mineral mining installation incorporating such a plough.
A conventional mineral mining installation consists of a scraper chain conveyor positioned alongside a longwall face, and a plough driven along a guide at the face-side of the conveyor by an "endless" chain. The chain is accommodated in guide channels defined within the guide, and passes over sprockets mounted on the drive frames at the two ends of the conveyor. At least one of these plough driven chain end sprockets is provided with a drive unit.
The disadvantage of this conventional installation is that it is not possible for the plough to mine material from the entire length of a longwall face. It is necessary, therefore, to mine material from the longwall face ends (the so-called "stable-holes") either manually or by means of special stable-hole ploughs, which considerably increase the cost of the installation. These stable-holes actually need to be cut away to a greater depth than that by which the face itself is worked, in order to accommodate the heavy and bulky drive units for the main plough and the conveyor.
Another known type of mineral mining installation utilises a conveyor whose ends curve through 90.degree., so that stable-holes (or galleries) can be formed at the longwall face ends by the main plough. Unfortunately, this installation requires additional heavy machinery. Another disadvantage is that the stable-hole tends to become crammed by the extended plough and conveyor sections. Moreover, the necessary deflection of the conveyor and plough chains in the curved regions develops high chain traction forces which results in a substantial increased wear of chains and guide devices.
The aim of the invention is to provide a mineral mining installation for winning material in a longwall working which enables the entire length of the longwall to be mined by a single plough and without the need for additional plant or expense to win material in the stable-hole regions.